RECOMBINANT HUMAN 92-KDA TYPE-IV COLLAGENASE GELATINASE FROM BACULOVIRUS-INFECTED INSECT CELLS - EXPRESSION, PURIFICATION, AND CHARACTERIZATION/

Human 92-kDa type IV collagenase/gelatinase (MMP9) has been expressed in insect cells and secreted into the cell medium via a baculovirus ex pression system. The expression level of the proenzyme from Trichoplus ia ni cells was estimated to be greater than or equal to 300 mg/L of c ell medium. The recombinant protein was purified in a single step usin g heparin-affinity chromatography with an overall yield of ca. 70%. Th e purified zymogen could be activated in vitro using 4-aminophenylmerc uric acetate to yield an active protease, Kinetic analysis of the acti vated recombinant enzyme demonstrates that this material is comparable to activated MMP9 from natural human sources. The recombinant enzyme provides a useful source of protein for a variety of biochemical and b iophysical studies aimed at elucidating the structure and function of human MMP9. (C) 1997 Academic Press.